Association between asporin gene aspartic acid repeat polymorphism and osteoarthritis: an updated meta-analysis

Objective: Osteoarthritis (OA) is a common disease characterized by progressive degeneration of articular cartilage. Several studies have been performed to evaluate the association between asporin gene aspartic acid repeat (ASPN D-Repeat) polymorphism and osteoarthritis susceptibility, but produced conflicting results. Our aim is to determine whether ASPN D-repeat polymorphism is associated with susceptibility to OA. Methods: A comprehensive literature search for all relevant studies was performed. The association between ASPN D-Repeat polymorphism and OA in each ethnic group was investigated. Sensitivity analysis and publication bias test were conducted. Results: Eleven studies with 8463 participants (4842 OA patients and 3621 controls) were enrolled in this study. The combined results revealed no significant association between D13 allele and the risk of OA (D13 allele vs. other alleles combined: OR 0.939, 95% CI 0.844-1.045). Subgroup analysis stratified by ethnicity and OA site further confirmed the irrelevance. The pooled results on the associations between other alleles (D14, D15, D16 and D17, respectively) and the risk of OA were similar to those of D13 allele, no significant association was identified in the overall population or in each subgroup population. Conclusion: This meta-analysis suggested that ASPN D-repeat polymorphism is not associated with OA susceptibility. Since potential confounders could not be ruled out completely, further well-designed studies are required.